Known revolvers employ a rotatable cylinder mounted in a rectangular aperture of a frame of the revolver for selectively positioning one of a plurality of rounds of ammunition in opposition to the firing bore of the revolver. The cylinder is typically rotatably mounted on a yoke of the revolver for selectively moving the cylinder in or out of the rectangular aperture of the frame during a loading or unloading operation.
For example, a known revolver includes a frame, a barrel, an ejector rod assembly and a cylinder having a plurality of longitudinal bores which are adapted to selectively position, in sequence, rounds of ammunition in opposition to the firing bore of the barrel. A yoke stud is integrally mated to the frame and provides an axis of rotation to selectively pivot both the yoke and the cylinder between an open position and its closed position. A spring biased ball plunger is integrally mated to the yoke and in communication with a ball cavity formed in the body of the frame for retaining the yoke and the cylinder in the closed position.
While successful to a certain degree, the interaction between the spring biased ball plunger and the ball cavity may experience sporadic, operational complications during and immediately following the discharge of a round of ammunition. When a round is discharged, the forces that propel the round down the length of the barrel exert a corresponding force in the opposite direction, that is, towards the rear, handgrip portion of the revolver. Although the effect of this opposite force is marginal on the interconnected elements of the revolver, the manufacturing tolerances inherent in the revolver permit a minute amount of structural translation to occur as a result of this incident and opposite discharge force.
The effect of the structural translation of certain elements in the revolver, as a result of the discharge of a round of ammunition and the associated manufacturing tolerances of the revolver, may cause the cylinder and the yoke assembly, to move slightly rearwardly, towards the handgrip portion of the revolver. The rearward movement of the yoke may cause the spring biased ball plunger to disengage from the ball cavity, thus facilitating the unintended pivoting of the cylinder from the closed position to the open position. The possibility of the spring biased ball plunger disengaging from the ball cavity may increase in proportion to the age of the revolver, owing to the increasing age and reduced resilience of the biasing spring, or the like, which serves to bias the ball plunger into contact with the restraining ball cavity.
There is, therefore, a need for a retaining mechanism to retain the cylinder within the rectangular aperture, especially subsequent to firing.
There is also a concern that firearms, and, in particular, revolvers, be designed so that the expended ammunition cartridge can be easily removed from the cylinder upon being discharged. Known revolvers employ an extractor, which disrupts the connection of the round of ammunition to the cylinder, in order to rapidly expel expended ammunition from the chamber of the cylinder. Said extractors are generally designed to avoid having any impact on the retention or release of the cylinder from the rectangular aperture of the frame. There is, therefore, a need for an improved extractor that works in conjunction with the retaining mechanism to promote retention of the cylinder in the rectangular aperture, especially subsequent to firing.
There is also a concern that, once the expended ammunition cartridges have been removed and new ammunition cartridges have been inserted into the cylinder, the retaining mechanism be designed so that the cylinder and yoke assembly can be easily pivoted from the open position to the closed position. There is, therefore, a need for an improved closing mechanism.